Investigators are probing the background of a Las Vegas police lieutenant who apparently killed his wife and son before setting his home on fire and taking his own life.

Police, firefighters and a SWAT team were called to a Boulder City, Nev., home Monday. The home, which is about 20 miles from Las Vegas, is owned by Hans P. Walters, 52, according to records from the Clark County Assessor's Office.

The names of the victims are expected to be released later today by the Clark County Coroner's Office.

The Henderson Police Department, along with the Las Vegas Metropolitan Police Department, confirmed the murder-suicide involved an off-duty, 52-year-old Las Vegas police lieutenant but did not release his name.

The events unfolded Monday morning when a man called 911 to say he had killed his wife and son, according to a news release from the Henderson Police Department, which is leading the investigation, since it has greater resources than Boulder City.

The caller said he was "going to set his house on fire and harm any officer that came to the home," the news release said.

When Boulder City police arrived, they saw a man standing in the doorway of the house, appearing to hold a handgun, according to Henderson police.

"The man refused to follow officers' commands and went back into the house. It is likely he then killed himself," according to the release.

SWAT officers were called to the scene and entered the home, where they found a man, woman and child dead.

The Boulder City and Henderson fire departments were called to the scene to battle the blaze.

"It's sad," a neighbor who lived across the street from the family told ABCNews.com, adding he "didn't really know them."

When Sheriff Douglas Gillespie of the Las Vegas Metropolitan Police confirmed the killings, fire and suicide on Monday in a brief news conference, he assured the families and friends of the victims, "We will stand by your side and move through this unspeakable grief and support you any way we can."